pmlogger_daily - Online in the Cloud

PROGRAM:

NAME

pmlogger_check, pmlogger_daily, pmlogger_merge - administration of Performance Co-Pilot
archive log files

SYNOPSIS

$PCP_BINADM_DIR/pmlogger_check [-CNsTV] [-c control] [-l logfile]
$PCP_BINADM_DIR/pmlogger_daily [-NorV] [-c control] [-k discard] [-l logfile] [-m
addresses] [-s size] [-t want] [-x compress] [-X program] [-Y regex]
$PCP_BINADM_DIR/pmlogger_merge [-fNV] [input-basename ... output-name]

DESCRIPTION

This series of shell scripts and associated control files may be used to create a
customized regime of administration and management for Performance Co-Pilot (see
PCPintro(1)) archive log files.

pmlogger_daily is intended to be run once per day, preferably in the early morning, as
soon after midnight as practicable. Its task is to aggregate and rotate one or more sets
of PCP archives. After some period, old PCP archives are discarded. This period is 14
days by default, but may be changed using the -k option. Two special values are recognized
for the period (discard), namely 0 to keep no archives beyond the current one, and forever
to prevent any archives being discarded.

Archive data files can optionally be compressed after some period to conserve disk space.
This is particularly useful for large numbers of pmlogger processes under the control of
pmlogger_check. By default no compression is done. The -x option enables compression and
specifies the number of days after which to compress archive data files, and the -X option
specifies the program to use for compression - by default this is xz(1). Use of the -Y
option allows a regular expression to be specified causing files in the set of files
matched for compression to be omitted - this allows only the data file to be compressed,
and also prevents the program from attempting to compress it more than once. The default
regex is ".(meta|index|Z|gz|bz2|zip|xz|lzma|lzo|lz4)$" - such files are filtered using the
-v option to egrep(1).

To accommodate the evolution of PMDAs and changes in production logging environments,
pmlogger_daily is integrated with pmlogrewrite(1) to allow optional and automatic
rewriting of archives before merging. If there are global rewriting rules to be applied
across all archives mentioned in the control file(s), then create the directory
$PCP_SYSCONF_DIR/pmlogrewrite and place any pmlogrewrite(1) rewriting rules in this
directory. For rewriting rules that are specific to only one family of archives, use the
directory name from the control file(s) - i.e. the fourth field - and create a file, or a
directory, or a symbolic link named pmlogrewrite within this directory and place the
required rewriting rule(s) in the pmlogrewrite file or in files within the pmlogrewrite
subdirectory. pmlogger_daily will choose rewriting rules from the archive directory if
they exist, else rewriting rules from $PCP_SYSCONF_DIR/pmlogrewrite if that directory
exists, else no rewriting is attempted.

The -r command line option acts as an over-ride and prevents all archive rewriting with
pmlogrewrite(1) independent of the presence of any rewriting rule files or directories.

By default all possible archives will be merged. The -o option reinstates the old
behaviour in which only yesterday's archives will be considered as merge candidates.

In the special case where only a single input archive needs to be merged, pmlogmv(1) is
used to rename the archive, rather than copy the input archive using pmlogger_merge.

The -M option may be used to disable archive merging (or renaming) and rewriting (-M
implies -r). This is most useful in cases where the archives are being incrementally
copied to a remote repository, e.g. using rsync(1). Merging, renaming and rewriting all
risk an increase in the synchronization load, especially immediately after pmlogger_daily
has run, so -M may be useful in these cases.

To assist with debugging or diagnosing intermittent failures the -t option may be used.
This will turn on very verbose tracing (-VV) and capture the trace output in a file named
$PCP_LOG_DIR/pmlogger/daily.datestamp.trace, where datestamp is the time pmlogger_daily
was run in the format YYYYMMDD.HH.MM. In addition, the want argument will ensure that
trace files created with -t will be kept for want days and then discarded.

In addition, if the PCP ``notices'' file ($PCP_LOG_DIR/NOTICES) is larger than 20480
bytes, pmlogger_daily will rename the file with a ``.old'' suffix, and start a new
``notices'' file. The rotate threshold may be changed from 20480 to size bytes using the
-s option.

Use of the -m option causes pmlogger_daily to construct a summary of the ``notices'' file
entries which were generated in the last 24 hours, and e-mail that summary to the set of
space-separated addresses. This daily summary is stored in the file
$PCP_LOG_DIR/NOTICES.daily, which will be empty when no new ``notices'' entries were made
in the previous 24 hour period.

The script $PCP_BINADM_DIR/pmlogger_daily could be copied and modified to implement a
site-specific procedure for end-of-week and/or end-of-month management for a set of PCP
archives.

pmlogger_check may be run at any time, and is intended to check that the desired set of
pmlogger(1) processes are running, and if not to re-launch any failed loggers. Use of the
-s option provides the reverse functionality, allowing the set of pmlogger processes to be
cleanly shutdown. Use of the -C option queries the system service runlevel information
for pmlogger, and uses that to determine whether to start or stop processes.

The -T option provides a terser form of output for pmlogger_check that is most suitable
for a pmlogger ``farm'' where many instances of pmlogger are expected to be running.

pmlogger_merge is a wrapper script for pmlogextract(1) that merges all of the archive logs
matching the input-basename arguments, and creates a new archive using output-name as the
base name for the physical files that constitute an archive log. The input-basename
arguments may contain meta characters in the style of sh(1). If specified, the -f option
causes all of the input files to be removed once the output archive has been created.

pmlogger_merge is used by pmlogger_daily.

Both pmlogger_daily and pmlogger_check are controlled by PCP logger control file(s) that
specifies the pmlogger instances to be managed. The default control file is
$PCP_PMLOGGERCONTROL_PATH, but an alternate may be specified using the -c option. If the
directory $PCP_PMLOGGERCONTROL_PATH.d (or control.d from the -c option) exists, then the
contents of any additional control files therein will be appended to the main control file
(which must exist).

Warning: The $PCP_PMLOGGERCONTROL_PATH and $PCP_PMLOGGERCONTROL_PATH.d files must not be
writable by any user other than root.

The control file(s) should be customized according to the following rules that define for
the current version (1.1) of the control file format.

1. Lines beginning with a ``#'' are comments.
2. Lines beginning with a ``$'' are assumed to be assignments to environment variables in
the style of sh(1), and all text following the ``$'' will be eval'ed by the script
reading the control file, and the corresponding variable exported into the
environment. This is particularly useful to set and export variables into the
environment of the administrative scripts, e.g.
$ PMCD_CONNECT_TIMEOUT=20
3. There must be a version line in the initial control file of the form:
$ version=1.1
4. There should be one line in the control file(s) for each pmlogger instance of the
form:

host y|n y|n directory args

5. Fields within a line of the control file(s) are usually separated by one or more
spaces or tabs (although refer to the description of the directory field for some
important exceptions).
6. The first field is the name of the host that is the source of the performance metrics
for this pmlogger instance.
7. The second field indicates if this is a primary pmlogger instance (y) or not (n).
Since the primary logger must run on the local host, and there may be at most one
primary logger for a particular host, this field can be y for at most one pmlogger
instance, in which case the host name must be the name of the local host.
8. The third field indicates if this pmlogger instance needs to be started under the
control of pmsocks(1) to connect to a pmcd through a firewall (y or n).
9. The fourth field is a directory name. All files associated with this pmlogger
instance will be created in this directory, and this will be the current directory for
the execution of any programs required in the maintenance of those archives. A useful
convention is that primary logger archives for the local host with hostname myhost are
maintained in the directory $PCP_LOG_DIR/pmlogger/myhost (this is where the default
pmlogger start-up script in $PCP_RC_DIR/pcp will create the archives), while archives
for the remote host mumble are maintained in $PCP_LOG_DIR/pmlogger/mumble.
10. The directory field may contain embedded shell syntax that will be evaluated by sh(1)
to produce the real directory name to be used. The allowed constructs are:
· Any text (including white space) enclosed with $( and ).
· Any text (including white space) enclosed with ` and ` (back quotes).
· Any text (including white space) enclosed with " and " (double quotes).
· Any word containing a $ (assumed to introduce an environment variable name).
11. All other fields are interpreted as arguments to be passed to pmlogger(1) and/or
pmnewlog(1). Most typically this would be the -c option.

The following sample control lines specify a primary logger on the local host (bozo), and
non-primary loggers to collect and log performance metrics from the hosts wobbly and
boing.

$version=1.1
bozo y n $PCP_LOG_DIR/pmlogger/bozo -c config.default
wobbly n n "/store/wobbly/$(date +%Y)" -c ./wobbly.config
boing n n $PCP_LOG_DIR/pmlogger/boing -c ./pmlogger.config

Typical crontab(5) entries for periodic execution of pmlogger_daily and pmlogger_check are
given in $PCP_SYSCONF_DIR/pmlogger/crontab (unless installed by default in /etc/cron.d
already) and shown below.

# daily processing of archive logs
14 0 * * * $PCP_BINADM_DIR/pmlogger_daily
# every 30 minutes, check pmlogger instances are running
25,55 * * * * $PCP_BINADM_DIR/pmlogger_check

In order to ensure that mail is not unintentionally sent when these scripts are run from
cron(8) diagnostics are always sent to a log file. By default, this file is
$PCP_LOG_DIR/pmlogger/pmlogger_daily.log or $PCP_LOG_DIR/pmlogger/pmlogger_check.log but
this can be changed using the -l option. If this log file already exists when the script
starts, it will be renamed with a .prev suffix (overwriting any log file saved earlier)
before diagnostics are generated to the log file. The -l and -t options cannot be used
together.

The output from the cron execution of the scripts may be extended using the -V option to
the scripts which will enable verbose tracing of their activity. By default the scripts
generate no output unless some error or warning condition is encountered.

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